Adaptation for rodent pollination in Leucospermum arenarium

Numerous studies have documented flower feeding in angiosperms and adaptions for non-flying mammal pollination, but the underlying interactions and structures that facilitate this pollination mode are less well known. Johnson and Pauw investigate the pincushion Leucospermum arenarium (Proteaceae) and find that the nectar is unusually viscous and, although produced deep inside the perianth, is translocated via capillary ducts to the petal tips where rodents can access it without destroying the flowers. Although flowers are presented at ground level, when raised experimentally to higher positions seed production is not reduced, indicating that selection through female function does not drive the evolution of geoflory. This reliance on rodent pollination has apparently evolved despite the fact that they are very adept at removing pollen through grooming.